Where did you get this information? From what I've heard the WinAPI will co-exist with the new .NET compatible API called Avalon. I don't believe Microsoft is going to scrap 10 years of software-compatibility.
The new version of windows, codename Longhorn, will not support WinAPI 32. That means MFC and all those API calls won't work. It will only support Windows Forms which is what C# uses (System.Windows.Forms namespace). Its also easier to learn than C++ and has a great editior (VS.NET).